A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

Purpose: This study was aimed to increase the quality of high dose rate (HDR) intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA) tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO), Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS) has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm) and depths (1.5-2.5 cm), different oesophagus applicators of relevant treatment lengths (6-10 cm) and depths (0.9 & 1.0 cm), and a bronchus applicator for relevant treatment lengths (4-7.5 cm) and depth (0.5 cm).Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32%) for rectum, 0.24% (standard deviation 2.36%) for oesophagus and 1.96% (standard deviation 0.55%) for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system

A phantom study for in-vivo dosimetry of high dose rate brachytherapy applicators

Purpose: The aim of the current investigation was to calibrate the diode in-vivo dosimetry (IVD) system for high-dose-rate (HDR) brachytherapy and to design a phantom study for in-vivo dosimetry of HDR brachytherapy applicators.Methods: Gamma Med Plus with Abacus 3.1 treatment planning system (TPS), and diode dosimetry system has been used in this study. Calibration and different correction factors of diode have been measured in water phantom. Treatment simulation, planning of different applicators for esophagus, rectum/vagina and cervix (fletcher & ring), dose delivery and finally in-vivo verification at prescription point using diode in water phantom has been performed.Results: The mean calibration factor for diode for Ir-192 HDR source is 1.256 (N=15) with σ ± 0.0015. The overall average percentage difference between TPS dose and diode dose was 1.87% (σ ± 2.64) for all measurements, 1.86% (σ ± 2.73) for esophagus, 1.86% (σ± 2.94) for rectum/vagina and 1.67% (σ ±2.81) for fletcher and 2.07% (σ ± 2.26) for ring applicators, respectively. These results advocate that the dose calculated by TPS and dose measured using diode for the various clinical situations deliberated here are in good agreement (~2%) at the points of clinical importance.Conclusion: The in-vivo phantom dosimetry study gives both a confidence that the treatments are being delivered as prescribed and enhance the reliability of the HDR brachytherapy treatment. This may be used for acceptance testing/commissioning of new treatment planning system and to validate the new brachytherapy techniques in the clinics.

A method for verification of treatment times for high-dose-rate intraluminal brachytherapy treatment

Purpose: This study was aimed to increase the quality of high dose rate (HDR) intraluminal brachytherapy treatment. For this purpose, an easy, fast and accurate patient-specific quality assurance (QA) tool has been developed. This tool has been implemented at Bahawalpur Institute of Nuclear Medicine and Oncology (BINO), Bahawalpur, Pakistan.Methods: ABACUS 3.1 Treatment planning system (TPS) has been used for treatment planning and calculation of total dwell time and then results were compared with the time calculated using the proposed method. This method has been used to verify the total dwell time for different rectum applicators for relevant treatment lengths (2-7 cm) and depths (1.5-2.5 cm), different oesophagus applicators of relevant treatment lengths (6-10 cm) and depths (0.9 &amp; 1.0 cm), and a bronchus applicator for relevant treatment lengths (4-7.5 cm) and depth (0.5 cm).Results: The average percentage differences between treatment time TM with manual calculation and as calculated by the TPS is 0.32% (standard deviation 1.32%) for rectum, 0.24% (standard deviation 2.36%) for oesophagus and 1.96% (standard deviation 0.55%) for bronchus, respectively. These results advocate that the proposed method is valuable for independent verification of patient-specific treatment planning QA.Conclusion: The technique illustrated in the current study is an easy, simple, quick and useful for independent verification of the total dwell time for HDR intraluminal brachytherapy. Our method is able to identify human error-related planning mistakes and to evaluate the quality of treatment planning. It enhances the quality of brachytherapy treatment and reliability of the system.</p